1. Field of the Invention
The invention is in the field of systems utilized to measure out and mix two or more fluids, including freely flowing fluids and viscous fluids, by delivering them simultaneously to a single location. More particularly, the invention's field concerns systems for simultaneously dispensing two nonhomogeneous materials from two syringes.
2. Description of the Prior Art
There are many types of procedures that require the mixing of two or more substances before the mixed compound can be used. For example, in the field of dentistry a common practice in the dental arts is to measure separate substances, drop-wise, into a well or mixing dish and to then mix the separate substances together using an applicator brush, which in turn is then used to apply the mixed compound to teeth surfaces. More recently, more advanced mixing and delivery applicator syringes have been devised that permit mixing to occur within the same syringe used for delivery. As will be appreciated, in dentistry, it is often necessary to mix relatively small amounts because of the small surface areas that are to be worked upon. Furthermore, the materials which are mixed are often expensive, and rather than mix large quantities, relatively small quantities are mixed repeatedly so as to not waste undue amounts of the materials in question.
There are circumstances in which it is desirable to dispense liquid or semi-liquid materials in a predetermined ratio. The materials may include reactive, two component adhesives, sealants, coating, or potting compounds, in which one material may comprise a resin compound and the other material a catalyst.
Clotting of blood in vivo takes place by conversion of the soluble plasma protein fibrinogen into fibrin, which spontaneously polymerizes into an insoluble gel matrix which may attach to adjacent tissue. The gel matrix stops bleeding and stabilizes structures. Thrombin catalyzed conversion of fibrinogen to fibrin can be reproduced in vitro and has great utility for adhering tissues and achieving hemostasis. Such fibrin sealants and fibrin glues are available commercially and are also made in blood processing laboratories. Preparation and use of fibrinogen-based sealants have been extensively reviewed.
Fibrin sealants, fibrin glues and adhesives based on combining fibrinogen-containing solutions with thrombin-containing solutions are used to reduce bleeding and restore hemostasis during surgical procedures. They have been known and in use for many years during which technology has evolved significantly. For example, fibrin clots can be made using different concentrations of fibrinogen in conjunction with the thrombin solution. Subsequent developments in technology include cryoprecipitate fibrinogen. Concentrated plasma can be used as the fibrinogen component in fibrin sealants.
Similarly, various types of applicators for fibrin glue are known. An optimal design is not obvious because of the chemical and biological properties of the liquid resulting from combining fibrinogen and thrombin solutions. Because of the rapid polymerization upon intimate interaction of fibrinogen and thrombin, it is important to keep separate these two blood proteins until application to the site of use. In practice, the two components are typically dispensed simultaneously from separate syringes and brought together by means of an applicator manifold.
With the known assemblies, a generally trough- or sleeve-shaped retaining means including appropriate troughs or sleeves for receiving the syringe bodies is provided to connect the syringe bodies, which retaining means, in addition, is provided with finger grips laterally projecting in opposite directions. The syringe bodies are inserted in these retaining means, wherein for instance, elastically yielding snap-in projections hold fast the syringe bodies. To actuate the pistons of the syringe bodies, the piston rods that are firmly connected with the pistons, furthermore, are connected with a common grip element, and, for stabilizing and improving the guidance of the piston rods when actuating the syringe device, it has also been proposed to connect a guide rod with the common grip element; such guide rod extends through a guide bore within the retaining means.
By such a design, a substantial progress in terms of simple mounting and greater safety in manipulation has been achieved as compared to earlier designs, such as according to U.S. Pat. Nos. 3,223,083 or 2,112,160, since, on the one hand, the syringe bodies may, for instance, be snapped in the retaining means and, on the other hand, the piston rods are interconnected for jointly operating the pistons and, moreover, are guided by the guide rod when moved such that a uniform actuation of the pistons of all of the syringe bodies will be ensured. By contrast, with the arrangement according to U.S. Pat. No. 2,112,160, the syringe bodies, which directly contact each other longitudinally, are connected in a complex manner by a cement mass as well as by wire loops and rubber bands. With the arrangement according to U.S. Pat. No. 3,223,083, the syringe bodies are connected with one another by a clamp enclosing them on a central point, wherein the syringe bodies do not assume a stable position relative to one another. Moreover, the two piston rods must be pushed forward by the user simultaneously and as uniformly as possible, which requires great skill.
In U.S. Pat. No. 5,290,259, there is disclosed a double syringe delivery system for holding a pair of syringes in a manner so as to accommodate the simultaneous activation of the plunger of each syringe in order to effect simultaneous delivery of the contents of each syringe, each syringe containing different contents. The double syringe delivery system includes an elongated support member that is placed between the barrel of each syringe. The elongated support member has resilient, C-shaped clamps on opposite sides of the support member. The clamps are used for holding the syringe barrels of both syringes so that the syringe barrels will be held together in a parallel manner. Further, elongated support member and clamps hold the syringe barrels in a fashion that is slightly longitudinally offset from one another to permit the two syringe barrels to be held together as closely as possible. An interconnecting bridge member connects the two syringe plungers so that they can also be simultaneously activated even though they are also slightly longitudinally offset from one another.